Little is known of his life. In 1584, Theoleptus supported Pachomius in the deposition of Patr. Jeremias II Tranos. However, Pachomius, who was unpopular with the Orthodox faithful, was deposed by a council of hierarchs on February 26/27, 1585, a synodal decision that the Sultan did not oppose, and was succeeded by Theoleptus as Patriarch of Constantinople.

As the patriarchs in Constantinople were under constant pressure to fulfill the financial demands of the Ottoman Turk government to obtain as well as retain their offices, Patr. Theoleptus, after replacing Patr. Pachomius II in 1585, sent two emissaries to Moscow, Russia to solicit funds to satisfy the demands of the government. By the time the emissaries returned, Patr. Theoleptus had been deposed and Jeremias II, a rival of Theoleptus, had returned as patriarch for the third time. [1]